151 citations · 613 across the 21 of their papers we have counts for
21 papers
Superradiant scattering of electromagnetic waves emitted from disk around Kerr black holes
Taichi Kobayashi, Akira Tomimatsu
We study electromagnetic perturbations around a Kerr black hole surrounded by a thin disk on the equatorial plane. Our main purpose is to reveal the black hole superradiance of ele…
Mechanical First Law of Black Hole Spacetimes with Cosmological Constant and Its Application to Schwarzschild-de Sitter Spacetime
Miho Urano, Akira Tomimatsu, Hiromi Saida
The mechanical first law (MFL) of black hole spacetimes is a geometrical relation which relates variations of mass parameter and horizon area. While it is well known that the MFL o…
Asymptotic behavior of dynamical variables and naked singularity formation in spherically symmetric gravitational collapse
Hayato Kawakami, Eiji Mitsuda, Yasusada Nambu +1
Considering gravitational collapse of matter, it is important problem to clarify what kind of conditions leads to the formation of naked singularity. For this purpose, we apply the…
Constraints on the Evolution of Black Hole Spin due to Magnetohydrodynamic Accretion
Masaaki Takahashi, Akira Tomimatsu
Stationary and axisymmetric ideal magnetohydrodynamic (MHD) accretion onto a black hole is studied analytically. The accreting plasma ejected from a plasma source with low velocity…
Disk illumination by black hole superradiance of electromagnetic perturbations
Taichi Kobayashi, Kohei Onda, Akira Tomimatsu
Using the Kerr-Schild formalism to solve the Einstein-Maxwell equations, we study energy transport due to time-dependent electromagnetic perturbations around a Kerr black hole, whi…
Breakdown of self-similar evolution in homogeneous perfect fluid collapse
Eiji Mitsuda, Akira Tomimatsu
The stability analysis of self-similar solutions is an important approach to confirm whether they act as an attractor in general non-self-similar gravitational collapse. Assuming t…